The present invention relates to an internal combustion engine fuel injector. In particular, the invention relates to an injector comprising a metering valve controlled by an electromagnet.
In known injectors of the above type, the armature of the electromagnet is normally connected to a stem guided by a sleeve fitted inside a cavity of the injector body together with the metering valve body. The core of the electromagnet, on the other hand, is fitted between a shoulder of a jacket and a disk supporting the discharge fitting of the metering valve, by deforming an edge of the jacket on the disk; and the jacket has an internal thread by which it is screwed to an external thread on the injector body.
Injectors of this type have several drawbacks. In particular, as the core of the electromagnet is made of sintered metal material and therefore relatively fragile, deforming the edge of the jacket on the core may result in damage to the core both at the edge and at the shoulder of the jacket.
Moreover, the deformed edge of the jacket fails to provide for fuel sealing, so that a seal is required between the core and the jacket; and, to complete the connection between the deformed edge and the disk, a cap of plastic material is required, which also incorporates the electric pin of the electromagnet coil.